1. Field of the Invention
The field of this invention is core body energy regulation.
2. Background of the Invention
Prolonged exposure to cold environmental conditions for extended periods of time can result in a condition known as hypothermia which can manifest itself in a variety of symptoms. The onset of symptoms is usually slow; there is likely to be a gradual loss of mental acuity and physical ability. The person experiencing hypothermia, in fact, may be unaware that he or she is in a state that requires emergency medical treatment. Symptoms include: apathy or lethargy, confusion, drowsiness, loss of coordination, pale and cold skin, shock, slowing of breathing, slurred speech, uncontrollable shivering, and weakness. As such, prolonged exposure to cold environmental conditions can result in significant adverse physical and mental effects.
There are a number of situations where it is desirable for a person to be exposed to cold environmental conditions for extended periods of time. For example, there are professions which require individuals to work under cold conditions, where such professions include, but are not limited to: professions that require prolonged time spent underwater, professions that require prolonged time spent outdoors in cold climates, and the like.
As such, there is great interest in the development of a technology that can maintain the core body temperature of a mammal at a substantially constant value for prolonged periods of time under cold conditions. Of particular interest would be the development of such a technology that accomplished the above results in a manner that was well-tolerated by the host, e.g., in a non-invasive manner that did not substantially impair the ability of the host to perform various tasks, e.g., work related tasks.
U.S. Pat. No. 5,683,438. See also WO 98/40039. Also of interest are: Soreide et al., xe2x80x9cA non-invasive means to effectively restore normothermia in cold stressed individuals: a preliminary report,xe2x80x9d J Emerg. Med. (1999 July-August)17(4):725-30 and Grahn et al., xe2x80x9cRecovery from mild hypothermia can be accelerated by mechanically distending blood vessels in the hand,xe2x80x9d J. Appl Physiol. (1998) 85(5):1643-8.
Methods and devices for preventing a change in the core body temperature of a mammal under cold conditions are provided. In the subject methods, a requirement for thermal energy input in said mammal is first detected. In response to the detection of this requirement for thermal energy input, a surface of a portion of the mammal is contacted with a warm temperature medium under negative pressure conditions for a period of time sufficient to introduce thermal energy into the core body of the mammal. The subject devices include at least a means for detecting a requirement for thermal energy input and a means for contacting a surface of the mammal with a warm temperature medium under negative pressure conditions. The subject methods and devices find use in a variety of applications, and are particularly suited for use in maintaining the core body temperature of a mammal substantially constant under cold conditions for an extended period of time.